Hydraulic fracturing is a complex process that involves many mechanisms; treatment procedures are affected by both natural and man-made conditions. The methods for wellbore completion (e.g. drilled, cemented, and perforated wellbores) have a strong influence on the fracture initiation and subsequent propagation. The fracture initiation and near-wellbore propagation contribute strongly to fracture configuration in far-field zone. (Here we define the far-field as a distance greater than 30 m from the wellbore). Reservoir porosity, permeability, saturation, and native pore fluid also influence the hydraulic fracturing results. In addition, formation heterogeneities, natural pre-existing fractures, joints, strata, etc. and the stress pattern are also the contributing factors. The actual far-field hydraulic fracture geometry is rather different from the simplified picture of a single bi-wing planar hydraulic fracture. This has been demonstrated by many data sets, including (1) core analysis; (2) mineback experiments, for example, experiments in coal formations, in which investigators mined into the formation after performing a hydraulic fracturing treatment to observe the actual fracture geometry and proppant placement; (3) microseismic tests; (4) wellbore video; (5) treatment pressure response; and (6) surface tilt meter measurements. Direct experimental data were complemented by the results of laboratory simulations, studies of natural hydraulic fracture analogues, and results from computer simulations. The single planar far-field fracture paradigm finds its roots and development in early theory and simplified laboratory studies that were predisposed to single, planar fracture geometry.
It is evident that proppant delivery to multiple branches, especially to the tips of branches, of a far-field fracture network can be improved by special techniques, for example, through ultra lightweight proppants delivery. There is a necessity for a simple and low-cost method for improving proppant suspension in a carrier fluid without the use of high-viscosity fluids. Here we describe such an improvement, namely, the reduction of the proppant settling rate during delivery to the far-field fracture network areas.